JVC HA-NCX77 Noise-cancelling

I recently bought these for half price at Argos, and the noise cancellation is useless!

I've tried them on a train and bus, amongst other places,  and there is NO difference with it turned on, except the volume is ever so slightly lower, but it doesn't suppress anything!   I have a pair of Goldring's and I wasn't expecting these to be as good, but honestly, the nc box is just a waste of space.

I assume they're not faulty as the light works and you can hear a faint click when you turn the nc on or off.

I shall be emailing JVC asking for their comments!